Slide fasteners are every-day items commonly referred to as zip fasteners, zippers or zips. By far the most common application of slide fasteners is as closure devices for bringing and retaining together two portions of clothing. With certain types of clothing such as foul weather gear, motorcycle clothing, hiking/mountaineering gear and the like it is desirable that the slide fasteners should have a degree of water resistance.
A number of water-resistant slide fasteners are known. For example, EP 0 345 799 A1 discloses a water-resistant slide fastener which is effectively a “double zip” having two superimposed pairs of coiled-type coupling elements, each pair of coupling elements being attached to a single stringer tape. This type of arrangement is relatively complex to make compared to a “standard” single slide-fastener arrangement. Moreover, the provision of a “double zip” arrangement tends to make the slide fastener of EP 0 345 799 A1 cumbersome to use as a result of the extra stiffness arising from two pairs of coupling elements in this arrangement.
GB 1,130,418 discloses a process for making a fluid-tight slide fastener wherein a conventional helical-coiled coupling element arrangement is subjected to an additional moulding process to produce two adjoined sealing strips along opposing rows of the helical-coil coupling elements. The sealing strips then are separated by a further process step of cutting the sealing strips using a blade. The process of GB 1,130,418 is relatively complex and requires a number of process steps and tooling requirements such as the provision of a cutting device to enable separating of the sealing strips which allows the slide fastener to be opened and closed (“unzipped” and “zipped”).
U.S. Pat. No. 4,724,586 discloses a water-resistant slide fastener comprising a conventional helical coil slide fastener having a pair of elongate reinforcing cores extending through the helical coil, and pair of stringer tapes to which the helical coil and reinforcing cores are stitched. The stringer tapes each have an extended lower margin which abuts against a corresponding lower margin of the opposing stringer tape so that when the slide fastener is in a closed condition, the extended lower margins of stringer tape press against one another to form a water-resistant seal there-between.
The slide fastener of U.S. Pat. No. 4,724,586 requires a number of extra components e.g. the reinforcing cores to be provided in addition to a standard helical coil fastener.